Vehicle Compatibility
Alternator voltage regulator for 24V Delco alternator applications using the 20SI, 21SI, 27SI and 30SI series where the alternator uses a matching 2 pin regulator layout with web and stud and a B+ bolt connection. This is a heavy-duty industrial regulator fitment and is typically identified by the alternator series and mounting format rather than a specific passenger vehicle model. Used across multiple plant, earthmoving, truck and industrial equipment applications where the Delco SI alternator reference matches. Confirm by alternator label (20SI/21SI/27SI/30SI) and the web/stud mounting before ordering.
- Delco Alternator Series: 20SI; 21SI; 27SI; 30SI (24V applications)
- Industrial / Heavy Duty (where alternator reference matches): Allis-Chalmers; Case; Caterpillar; Clark; Cummins; Earthmoving; Euclid CH120; Euclid CH130; Euclid CH135; Euclid EH1600; Euclid R170; Fiat; Industrial; Ingersoll Rand; International Eagle; International Harvester; Komatsu; Locomotive; Mack; Oshkosh; Terex; Volvo
Specifications
- Reference: REG2624
- Part Type: Alternator Voltage Regulator
- System Voltage: 24V
- Regulated Voltage (Set Point): 27.5V (VS=27.5V)
- Manufacturer: Bosch Type
- Alternator Series: Delco 20SI / 21SI / 27SI / 30SI
- Circuit: A-Circuit
- Type: IR/EF (Internal Regulator / External Fan)
- Connector / Pins: 2 Pin With Web And Stud
- B+ Connection: 1P B+ (Bolt)
Features
- 24V regulator specification for Delco 20SI 21SI 27SI and 30SI alternator series
- Web and stud mounting format with B+ bolt connection for heavy duty alternator housings
- A-circuit IR/EF control strategy commonly used in industrial Delco SI alternator builds
- 27.5V set point (VS=27.5V) to maintain stable charging on 24V electrical systems
- Supports alternator overhaul where regulation faults cause low charge, overcharge, or unstable system voltage
Why Buy From Us
- Local South African stock with nationwide courier delivery
- 12-month warranty subject to correct application and installation
- Fitment support using alternator labels and clear photos of the existing regulator mounting and plug layout
- Trusted by workshops and fleet operators for dependable charging system components
Trusted by thousands of South African drivers for quality and durability.
Installation & Maintenance Tips
- Isolate the batteries and confirm the system is 24V before alternator or regulator work
- Confirm the alternator series (20SI/21SI/27SI/30SI) and the web/stud mounting format before fitting
- Inspect brushes, slip rings, internal connections and earth points during overhaul and replace worn components as required
- Ensure B+ and earth connections are clean and tight to prevent voltage drop and repeat failures
- After installation, verify charging voltage under load and confirm stable system voltage
- If you are unsure about alternator repairs on heavy duty systems, have the unit fitted and tested by a qualified auto electrician
